From beafe961479d4c7380e3c0dab4b18bcf60d29255 Mon Sep 17 00:00:00 2001
From: Kyle Evans <kevans@FreeBSD.org>
Date: Sun, 25 Feb 2018 17:02:50 +0000
Subject: [PATCH] lualoader: Track the menu currently drawn, instead of
 validity

This cleans up the odd approach to menu drawing. Instead of tracking
validity, we track the menu that was drawn on the screen. Whenever we draw a
menu, we'll set this to that menu.

Anything that invalidates the screen should go ahead and trigger an explicit
redraw, rather than finding a wy to set screen_invalid.

The currently drawn menu is then reset in menu.run as we exit the menu
system, so that dropping to the loader prompt or leaving menu.run() will
just behave as expected without doing redundant work every time we leave a
menu.
---
 stand/lua/menu.lua | 24 +++++++++---------------
 1 file changed, 9 insertions(+), 15 deletions(-)

diff --git a/stand/lua/menu.lua b/stand/lua/menu.lua
index d707ab5a6bed..1a6ca97a9f57 100644
--- a/stand/lua/menu.lua
+++ b/stand/lua/menu.lua
@@ -38,7 +38,7 @@ local drawer = require("drawer")
 
 local menu = {}
 
-local screen_invalid = true
+local drawn_menu
 
 local function OnOff(str, b)
 	if b then
@@ -82,7 +82,6 @@ menu.handlers = {
 		end
 	end,
 	[core.MENU_SUBMENU] = function(_, entry)
-		screen_invalid = true
 		menu.process(entry.submenu)
 	end,
 	[core.MENU_RETURN] = function(_, entry)
@@ -348,12 +347,12 @@ menu.default = menu.welcome
 -- the local alias_table in menu.process.
 menu.current_alias_table = {}
 
-function menu.redraw(m)
-	-- redraw screen
+function menu.draw(m)
+	-- Clear the screen, reset the cursor, then draw
 	screen.clear()
 	screen.defcursor()
 	menu.current_alias_table = drawer.drawscreen(m)
-	screen_invalid = false
+	drawn_menu = m
 end
 
 -- 'keypress' allows the caller to indicate that a key has been pressed that we
@@ -361,10 +360,8 @@ end
 function menu.process(m, keypress)
 	assert(m ~= nil)
 
-	-- Trigger a redraw if we've been invalidated.  Otherwise, we assume
-	-- that this menu has already been drawn.
-	if screen_invalid then
-		menu.redraw(m)
+	if drawn_menu ~= m then
+		menu.draw(m)
 	end
 
 	while true do
@@ -404,13 +401,9 @@ function menu.process(m, keypress)
 			end
 			-- If we got an alias key the screen is out of date...
 			-- redraw it.
-			menu.redraw(m)
+			menu.draw(m)
 		end
 	end
-	-- Invalidate the screen upon exit so that it gets redrawn upon
-	-- processing a new menu, assuming it won't be redrawn after leaving
-	-- this menu
-	screen_invalid = false
 end
 
 function menu.run()
@@ -419,10 +412,11 @@ function menu.run()
 		return
 	end
 
-	menu.redraw(menu.default)
+	menu.draw(menu.default)
 	local autoboot_key = menu.autoboot()
 
 	menu.process(menu.default, autoboot_key)
+	drawn_menu = nil
 
 	screen.defcursor()
 	print("Exiting menu!")